What ideas and feelings does lord capulet convey in the simile in lines 28–29?

In these lines, Capulet uses a simile in which he compares Juliet to the "sweetest flower of all the field." This phrase conveys the beauty and the delicate nature of Juliet. It also conveys Capulet's deep love for his daughter. However, he also tells us that "death lies on her like an untimely frost." The fact that the death is "untimely" shows that Capulet thinks Juliet was too young to have died. The idea of a frost contributes to the tone of the excerpt by contrasting something sweet and beautiful as the flower (Juliet) with the destructive harshness of the frost (death).

absolutely it most certainly can.